I find that in other cards of this deck the full moon represents a sense of fullness or completion. Therefore I think this represents how the Lovers complete each other. They feel like they are two halves of a whole, and they are only complete when they are together.

I think the themes of red and fire in this image do suggest passion, but also destruction. I think the red moon and the scene below them of fiery destruction suggests that a love that is too obsessive and all-consuming may be dangerous. I think it also might suggest that many relationships, no matter how strong the love seems to be, do meet a painful end. Maybe this card is a warning that love can inspire great passion, but it can also lead to great pain if the relationship does not end well.